Preheat your oven to 400°F. Prepare a cookie tray with parchment paper or a silicone baking mat for easy cleanup.

In a medium bowl, mix together the flour, baking soda, cream of tartar, and salt. Set this aside for later.

In a big mixing bowl, cream the softened butter and 1 1/2 cups of sugar until it's light and fluffy, about 2-3 minutes.

Add the eggs, one at a time, beating well after each addition. Don't forget to scrape down the bowl to get everything mixed together!

Stir in the vanilla extract until everything is well blended.

Gradually mix the dry ingredients into the wet mix until just combined.

In a small bowl, combine the remaining 3 tablespoons of sugar with the ground cinnamon.

Scoop out 1 tablespoon of dough and roll it into a ball. Coat each ball in the cinnamon-sugar mixture and place them on the prepared baking sheet, spacing them about 2 inches apart.

Bake for 6-8 minutes until they’re just set and slightly golden.

Let the cookies cool on the tray for 2-3 minutes before transferring them to a wire rack to cool completely.